Saltwater Pool Maintenance: Troublefree Saltwater Swimming Pool
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Having a Trouble Free Saltwater Swimming Pool
From my experience with saltwater pools; the major troubles with saltwater swimming pools are low chlorine, low salinity, salt chlorinator maintenance, and corrosion: That is all this post is about.
Having a trouble free saltwater swimming pool is not a rocket science; it’s all about monitoring and testing chemicals used in the pool regularly(at least weekly), and regular maintenance of saltwater chlorine generator (SWCG).
Water chemistry for a saltwater pool is not complicated as pure chlorine-based swimming pool: And if you do it right; you will never have common pool problems such as algae growth, cloudy or green pool water that will require your pool to be shocked using harsh chlorine.
Saltwater pool has the minimal pool maintenance requirements than regular chlorine based pool and that is a fact: However, in most case, people have problems with their saltwater pool if they have chemicals out of balance, or rarely when there is a problem with a saltwater chlorine generator.
Based on my experience with saltwater pool for more than 4 years now; I have compiled every loophole that may cause a problem in your saltwater pool like low salinity and chlorine reading and all the workarounds on how to avoid these problems from occurring anytime.
Saltwater Pool Chemistry
1. Salt Concentration (Salinity)
A saltwater pool system will operate efficiently only when salt is in the right concentration. Different saltwater chlorine generators will need different salinity levels, and this is the first thing you need to take in consideration before adding or reducing salt in your pool.
Chlorine generators will operate just fine with salinity levels between 2500 and 3500 ppm. To be sure with the salinity level in the pool water before adjusting, you need to have accurate salt water test kit or strip like . LaMotte 1749 Salt PockeTester
Alternatively, you can use SWCG that monitors and display the salinity reading. However, swimming pools in cooler temperature regions will reduce water conductivity, and if you are taking the reading of salinity from the generator you may get a much lower reading which is actually not the case and you need to be careful as you can add too much salt.
Most importantly, ensure that you don’t add too much salt into the pool since the only way to reduce salinity is by draining the pool water and refilling with fresh water.
You can test for salinity on a weekly basis: However, salt in the pool will be recycled during the process of chlorine production, and you may not need to add salt unless the level goes way down the recommended range.
Here is salinity calculator that will guide you on the correct amount of salt to add to your pool to avoid excess salinity.
2. pH levels
Just like a regular chlorine based swimming pool; ideal pH levels is necessary to enable chlorine function effectively in killing harmful bacteria that thrive in the pool.
Ideally, the recommended levels of pH should be between 7.2 and 7.6 ppm, with the most ideal or optimal level of 7.4 ppm.
To reduce pH levels when out of balance, you can use muriatic acid (liquid hydrochloric acid) or dry acid such as sodium bisulphate.
To increase pH, you can use alkali such as soda ash: Ensure that you add these substances into the pool slowly in increments and allow the water to circulate for 4-6 hours before using the pool
3. Free Available Chlorine
Just like non salt water pool system; you need to monitor free chlorine levels by testing it on a regular basis: The recommended free chlorine levels should be between 2-3 ppm all the time.
As such, if your free chlorine goes below the recommended levels; you need to measure salinity level and ensure that you increase it if it is below the recommended levels, before even thinking of adding chlorine shock into your pool.
Very low salinity levels may bring down your available free chlorine to 0 pmm; which should not be the case as algae may thrive in the pool.
Apart from low salinity levels; low free chlorine can be caused by calcium buildup on the salt cell, an expired salt cell, excess stabilizer, or poor pool circulation.
If the salinity level and everything mentioned above is just fine but free chlorine is too low, that may be as a result of heavy pool usage and you may add small amount of regular chlorine, or adjust your chlorine generator to produce more chlorine if it’s running at a lower percentage: More about SWCG maintenance to follow.
4. Total Alkalinity
Monitoring total alkalinity (TA) is as important as any other chemical in the swimming. TA in the swimming should be kept between 80 and 120 ppm to help keep pH stable especially in rainy seasons.
Very low total alkalinity may lead to corrosion, metal staining, calcium scaling, and sometimes may cause green pool water. On the other hand, high TA will cause cloudy or murky pool water and pH fluctuation.
To raise the total alkalinity, you can use sodium bicarbonate; and hydrochloric acid or muriatic acid to lower it. However, you should be careful when adding these reagents as they also have the same effect on pH.
Sometimes balancing pH and TA can be so hectic; and the only way to balance the two may be through aeration process, which works by reducing both using muriatic acid and then raising pH through aeration to get the correct balance between the two.
If possible, always avoid stabilizer unless you have an outdoor pool, or your pool is located in area with hot and humid climate.
Stabilizer is mainly used to help keep free chlorine stable, by protecting it from exhaustion by sunlight and high water temperatures.
The recommended levels of stabilizer mainly Cyanuric acid, is between 40 and 80 ppm for saltwater pools.
The correct value of Cyanuric may also differ with geographic locations, depending on temperature and how much sunlight is available during the day.
This explains precisely why a saltwater pool in Canada will need between 40 and 60 ppm of Cyanuric acid and a saltwater pool in USA may need up to 80 ppm of Cyanuric acid.
Also, the amount of Cyanuric acid to use will depend on the amount free available chlorine in the pool water.
Very high Cyanuric acid will reduce the levels of free chlorine; you can use this Cya/Chlorine chart to determine the correct level of Cyanuric acid to add to what amount of available free chlorine.
I recommend: LaMotte ColorQ Pro 7 Digital Pool Water Test Kit
6. Total Dissolved Solids (TDS)
This is the most ignored pool water chemistry. The TDS in your pool whether saltwater pool or pure regular chlorine based pool should not exceed 1500 ppm.
The levels of TDS increases as chemicals are added into the pool and as other organic matters dissolve in the pool water.
TDS significantly affect the free chlorine levels and other chemicals in the pool if they drift on a higher side than the recommended level; TDS also causes cloudy pool water.
To reduce TDS in the pool water, the only solution is to drain the pool water and replace it with fresh water, or increase the frequency of backwashing and cleaning your pool filter: If you need accurate TDS tester, you can order LaMotte 1749 Salt/TDS/Tempereture PockeTester in the dislplay above from Amazon.
Saltwater Chlorine Generator (SWCG) Maintenance
SWCG maintenance is all about cell cleaning and replacement, period: Chlorine production happens in the saltwater pool cell, and defective salt cell will lead to less or no production of chlorine that should be added into the pool.
As such, you need to closely monitor the salt cell to ensure that there is no calcium buildup, which causes low production of chlorine.
Ideally, even if there is no buildup in the cell, it is recommended to clean your salt cell at least every 6 to 12 months.
Most modern cells such as ones from Hayward Salt Chlorinators will have a self-cleaning feature that makes it easy to clean anytime.
I use Hayward Salt Chlorinator and they have a very inclusive guide on how to clean salt chlorinator turbo cell.
However, here is a step by step 10 minutes general guide on to clean saltwater pool cell:
Step 1: Turn off all power
Step 2: Remove the cell plugs
Step 3: Remove the cell from the casing using crew driver to unscrew
Step 4: Add sufficient muriatic acid in a bucket of water: Avoid too much acid as it may reduce your cell life (about 6 oz of muriatic acid per quarter bucket of water is ok)
Step 5: Pour the solution into the cell and leave to soak 5 to 10 minutes
Step 6: Dispose of the acid solution and rinse the cell with a garden hose
Step 7: Reinstall the cell back
Finally; expired salt cell also is one of the major causes of problems in a saltwater pool: The average lifespan of a salt cell is 3-5 years in most SWCGs, after which you need to replace the old cell with a new one that will produce sufficient chlorine.
How to Clean Hayward Salt Cell
Setting Appropriate Percentage to Run SWCG
Basically, all Saltw Chlorine Generators are designed to provide a percentage setting that controls how much chlorine to produce; and the percentage of the time that the pump should run to enable production of chlorine.
Generally, to produce more chlorine; you need to increase the percentage, and reduce the percentage when you need less production of chlorine.
In some cases, you will be forced to increase the pump run time to allow for the production sufficient chlorine when free chlorine is too low.
However, since the setting is a percentage of the pump runtime, you will have to readjust the percentage every time you change the pump run time to get free chlorine from low to recommended levels.
Handling Corrosion/Metal Stains in Saltwater Pool
Saltwater pools are fond of forming faded pool surfaces and metal stains or corrosion on steel hardware pool parts.
Also known as a sacrificial zinc anode; protects metals that are in contact with saltwater in a swimming pool.
Its major function or how it works is that it corrodes or sucrifice itself before any other metal that is part of the pool underwater electrical system that can catch metal stains.
You need to check on the anode at least on a yearly basis to ensure that it has not degraded fully.